Lining implement



Nov. 22, 1938. G. H. COLBURN LINING IMPLEMENT Filed Nbv. s, 1956 Patented Nov. 22, 1938 UNITED STATES PATENT oFFicE 3 Claims.

This invention pertains to the photographic art invention is found of particular value for ruling lines upon a photographic negative when, for example, the ultimate printing surface is to be employed in the printing of ruled forms such as account book and ledger pages, index cards, ruledpaper or the like, having parallel horizontal lines, some of which may be double or triple lines, and also frequently having intersecting vertical lines some of which may be single, and others double or triple, depending upon the use to which the form is to be put.

The requisite lines upon the photographic znegative are produced by removing the exposed developed emulsion from the underlying glass or Celluloid support so as to leave clear transparent lines upon a dark and substantially opaque background, but such removal of the developed gelatin film, so as to leave evenly cut sharp lines, particularly if such lines must be very narrow and spaced closely together, is not at all easy. So far as is known, no satisfactory tool or instrument has heretofore been devised for this purpose.

The ruling of lines upon a negative in accordance with prior practice has usually been carried out as a hand operation, the incising instrument being drawn along a straight edge after the manner of a ruling pen. The instrument in common use for this purpose is usually made from a piece of hack saw blade which is reduced in thickness by grinding on one or both sides and which is shaped in accordance with the ideas of the particular user so as to provide a cutting edge .of the width and form deemed most suitable for the purpose. However, it is to be noted that when the desired thicknessat the cutting edge is produced by grinding off the material at the sides, the end portion usually tapers in thickness, and when drawn along a straight edge the tip of the blade may rock toward and from the vertical plane of the straight edge, thus producing a wavy and irregular line. Further, such grinding of the tool to the requisite thickness is a troublesome matter, requiring a greater degree of mchanical skill than is always available in shops where such tools are employed, and if the cutting edge is repeatedly sharpened it tends to increase in effective width and thus produces a thicker line than intended. .Moreover, in accordance with such prior practice,

the cutting edge has usually been of chisel form and with square corners, a shape which has not been found wholly suitable for the removal of the tough elastic film in such a way as to produce sharp lines with accurately straight edges.

Furthermore, in using such makeshift implements as have previously been employed, the production of double and triple lines necessitates repeated closely spaced rulings, and in View of the inaccuracies inherent in the prior method of procedure, it has been found almost impossible to rule double or triple lines with the desired closeness of spacing without merging the lines here and there, a result which greatly detracts from the appearance of the printed form prepared by the use of such a ruled negative.

The principal object of the present invention is to provide an incising implement for the general purpose described, such that sharp, cleanlines of any width (within the range usually employed in printing) may readily be cut into a photographic negative without requiring high skill upon the part of the operator and with reasonable certainty that such lines will be accurately straight and of uniform width, with clean-cut sharp mar gins and of a uniform depth such as to remove substantially all of the emulsion from the supporting glass or Celluloid.

A further object is to provide an incising cutter or blade which maintains the desired width of cutting edge regardless of the number of times that it may be sharpened; which does not require any grinding of its lateral surfaces to produce the desired width of line; which may be held firmly against a straight edge without tendency to tip in one direction or the other; and which may be removably mounted in a suitable handle or holder so as readily to be exchanged for another blade of different width. A further object is to provide an improved cutter or incising implement capable of concomitantly cutting a plurality of parallel lines uniformly spaced apart at all points. A further object is to provide a holder or handle for the improved cutters or blades, so designed as to assist the user in presenting the cutter edge of the blade at the proper angle to the work.

Further objects and advantages of the invention will be pointed out hereinafter in the following more detailed description and by reference to the annexed drawing in which Fig. 1 is a side elevation, with certain parts broken away, illustrating the improved incising cutter mounted in a desirable form of holder, the

cutter shown being designed or cutting triple lines;

Fig. 2 is an end elevation looking from the right-hand end of Fig. 1;

Fig. 3 is an enlarged side elevation, partly broken away, showing the improved cutter removed from the holder,

Fig. 4 is a plan view of the cutter of Fig. 3;

Fig. 5 is a plan view, showing a single cutter or blade arranged to be held in a handle such as that of Fig. 1 and designed for incising a single line;

Fig. 6 is a similar cutter, but designed for concomitantly cutting parallel lines of equal width;

Fig. 7 is a plan view of a similar cutter but having two blades designed concomitantly to out two lines of different width;

Fig. 8 is a fragmentary side elevation partly in section, illustrating the action of the improved cutter in removing the film from the supporting glass or Celluloid; V

Fig. 9 is a section to very greatly enlarged scale substantially on the line 9-9 of Fig. 8, showing a preferred shape for the cutting edge of the blade; and

Fig. 10 is a fragmentary plan view, illustrating the appearance of a photographic negative ruled by the use of this improved implement.

Referring to the drawing, the numeral i designates a handle or holder designed for securely holding any one of a set of interchangeable cutters. This handle may be made of any suitable material such as wood or metal, and is preferably of generally triangular cross section, as illustrated in Fig. 2, comprising the fiat sides 2, 3 and 4.

Preferably the angles of the triangle are truncated so as, for example, to form a flat surface 5 substantially parallel to the surface 2. The holder is provided at one or both ends with a tool holding chuck of any appropriate type. For example, the chuck may comprise a pair of spaced parallel jaws 6 and 1 and a knurled internally screwthreaded collar designed to draw the jaws 6 and 1 toward each other so as to clamp a cutter between them. Preferably these jaws 6 and l are so arranged that when a cutter is mounted in the handle, the plane of the cutter blade will be substantially perpendicular to the surface 2 of the handle and if a single blade be employed, the plane of such blade will bisect the angle between the sides 3 and 4. Such an arrangement permits the user very readily to determine the proper position of holding the handle, in order that the cutting edge of the blade may be truly horizontal or parallel to the surface of the work.

As illustrated in Figs. 1 to 4, the cutter 9 comprises three blades lfl, I l and I2, disposed in parallel relation and of the same dimensions. Each blade comprises a shank portion Ill ll and I2, respectively,and these shank portions are held in properly spaced relation by means of interposed spacer blocks 13 and M. The blocks and the shank portions of the blades are preferably permanently united after assembly so as collectlvely to form the shank of the three-bladed cutter by means of rivets or other types of inserted fastener, but preferably by spot welding, as indicated at l5 (Fig. 3).

Each of the blades, for example the blade i l, as illustrated in detail in Fig. 3, consists of a generally rectangular elongate strip of sheet metal. Sheet metal is commercially available in almost any desired thickness, varying in gauge by thousandths of an inch, so that it is possible to obtain metal in sheet form of a gauge which corresponds final thickness it is merely necessary to select sheet material of the proper gauge, and then by a stamping, punching or other similar operation, to cut out blades of desired contour and with certainty that they will have the desired accurate thickness. By such procedure it becomes unnecessary to use any grinding or other operation for reducing the blades to the final desired thickness.

Preferably, in forming the blade in accordance with the present invention, the corners I5 and 15 of the original substantially rectangular blank are cut away and the tip end is finished to have a rounded contour, as shown at I! thereof. However, this latter feature is not essential. In cut-- ting away the corner l6 of the blank the metal is so removed as to provide a work-engaging surface or edge H! which is tangent to the rounded tip and which preferably makes an included angle of the order of 32 with the adjacent edge I9 of the blank. A notch 20 is also cut in this same edge of the blank, such notch preferably being of generally triangular shape having one side 2| making an angle of approximately 30 with the edge 19 of the blank and having another side 22 which intersects the edge I 9 of the blank at the same point 23 at which the surface [8 intersects said edge 19, this line of intersection at the point 23 constituting the cutting edge. Preferably the included angle between the side 22 of the notch and the surface I8, is of the order of As may be noted, the cutting away of the corners l5 and N5 of the blank, and the provision of the notch 21], reduces the end of the blank to a hook-like shape, the angle between the lines l8 and 22 defining the beak of the hook with the cutting edge 23 at the tip of the beak.

Following the above method of procedure the cutting edge 23 extends transversely across the entire thickness of the blade, and if it be desired either initially or during use to sharpen the blade, it is merely necessary to'deepen the notch 20, in particular removing material from the side 22 of the notch without substantially changing the angle between such side and the work-engaging surface l8, and without in any way varying the effective transverse length of the cutting edge 23.

Preferably the corners of the blade at the ends of the cutting edge are slightly rounded, as indicated at 24 and 25, respectively, (Fig. 9), such rounding or smoothing of these corners preventing the tearing or milling of the gelatin film as the cutter is drawn through it. However, it is to be understood that this rounding of the corners 24 and 25 is but little more than a smoothing or burr-removing operation and that the radius of curvature in these corners is very small.

After the blade has thus been prepared it may, if desired, be hardened and tempered or otherwise heat treated to make it hard, tough and wear-resistant. On the other hand, it is contemplated that the blade may be given a hard wearresistant surface, for example by chrome plating, although in such case it may be necessary to seleot sheet material of such slightly lesser thickness than that of the finished plate as to compensate for the thickness of the plating. It is further contemplated that steel of the variety known as stainless steel may be used and prop- Whatever method be employed for finishing the blade, it is to be understood that after it has thus been finished it will be assembled with semblage, and union of the blades the cutting,

edges of the several associated blades may be simultaneously ground or honed, so that such cutting edges will be in accurate alignment.

In Fig. 6 a cutter is illustrated comprising but two blades Ill and Hwith a spacer l3 interposed between them and with filler members l3 and M similar to the spacer but disposed at the outer sides of the blades Ii] and M, respectively, such =-filler members being of a. thickness such that when the blades, the spacer and the fillers are assembled, the transverse thickness of the shank portion of the resultant cutter will be the same as that of the cutter of Fig. 4 so that it may be fitted into the same chunk as the latter.

In Fig. 5 a cutter with a single blade I l is illustrated, and in this case filler members I3 and M are shown as disposed at opposite sides of the shank of this blade, such fillers being secured to the blade and being of such thickness that the assemblage is of the same transverse width as that of Figs. 4 and 6.

In all of the cutters above described the blades are of the same thickness so that their cutting edges are all of the same length and would produce lines on the negative of the same width.

However, as illustrated in Fig. 7, the cutter may be devised so as simultaneously to produce lines of different width. Thus as shown in this figure, the cutters l I and l I are of different thicknesses, a spacer I3 being interposed between them and filler members M and It) being assembled with the blades and spacer so as to form a cutter having a shank of the same standard thickness as those previously described and adapted to be received in the same holder or handle. Obviously any other desired assemblage of blades of different thicknesses and with spacers of different thicknesses interposed between them may be made in accordance with the invention.

In using the device, assuming that a cutter has been mounted in the handle, the user grasps the handle in such a way that the surface 2 is uppermost and holds the implement so that its longitudinal axis preferably makes an angle of approximately 30 with the surface of the negative 2'! which is to be lined. Assuming that the negative has been placed upon a horizontal support and that a straight edge is available for guiding the cutter, the operator (thus holding the implement at the angle indicated) brings the vertical outer face of the cutter blade into contact with the straight edge and then, while holding the tool in the inclined position suggested, draws the tool along the straight edge thereby incising the film of gelatin 2% and removing this film from the support 28 as a narrow chip so as to leave a clear transparent line upon the negative. When using a duplex cutter such as that of Fig. 6, two closely spaced parallel lines will be formed simultaneously, asindicated at 29 (Fig. On the other hand, when using a cutter ,having a single blade, a single line will be cut face. 18 of the blade travels along the work and provides a support for the, implement. However, such work-engagingsurface usually engages the support 28 only adjacent to the cutting point,

usually making an angle of the order of 2 with the surface of the support 28. Apparently this is the most effective angle of operation, although it is to be understood that the tool may be rocked slightly in a vertical plane in accordance with the condition of use whereby to obtain the maximum efficiency under any given set of conditions. By making an angle of approximately 90 between the surface l8 and the side 22 of the notch it becomes substantially impossible to dig the cutting edge'so deeply into the work as, for example, to gouge into a support of Celluloid or the like upon which the gelatin may be mounted.

Since the cutting edge 23 is accurately perpendicular to the side face of the blade which comes in contact with the straight edge, theimplement does not tend to rock so as to produce a wavy line, and thus it is possible to produce lines which.

are accurately straight even though the cutter is operated by hand and merely guided by a straight edge. Moreover, as already pointed out, since the transverse length of the cutting edge is a fixed dimension not subject to change by sharpening the tool, it is certain that throughout the useful life of the blade it will always produce a line of the same accurate width.

As already noted, the invention contemplates the provision of a holder or handle and a set of interchangeable cutters (having shank portions of like dimensions) designed to produce any desired width or combination of lines, and thus the user, without difficulty and without loss of time,

is enabled to rule the negative in accordance with any predetermined pattern and without the necessity of resorting to intermediate sharpening of the tool or other slow, laborious process requiring mechanical skill for its proper accomplishment.

While certain desirable embodiments of the invention have been illustrated by way of example, it is to be understood that the invention is not necessarily limited thereto, but that all equivalents are to be regarded as within the purview of the invention, as expressed in the appended claims.

I claim:

1. A cutter for lining a photographic negative or the like, comprising an elongate handle, a holder at the end of the handle, a cutting tool removably mounted in said holder, said tool comprising a sheet metal blade having a substantially uniform thickness so that its opposite faces are parallel, the blade having an arcuate end surface and an adjoining edge surface constituting a work-engaging surface, the blade having a second edge surface extending at an angle of the order of 90 to said work-engaging surface and meeting the same at an intersection line toafford a cutting edge, said line extending across substantially the entire width of the blade, said work-engaging surface extending at an angle of the order of 30 to the direction of extent of said handle, whereby the tool may be drawn by said handle over a coated negative with the work-engaging surface engaging the face of the negative and said second surface substantially perpendicular thereto.

2. A cutter for lining a photographic negative or the like, comprising an elongate handle, a holder at the end of the handle, a cutting tool removably mounted in said holder, said tool comprising sheet metal .blades with spacers therebetween, each of said blades having a substantially'uniform thickness so that its iopposite'faces are parallel, each blade having an arcuate end surface and an edge surface tangential thereto constituting a work-engaging surface, each blade having a second edge surface extending at an angle of the order of 190 to its work-engaging surface and meeting the same at an intersection line to afford a cutting edge, said line extending across substantially the entire width of the blade, said work-engaging surface extending at an angle of the order of 30 to the direction of extent of said handle, "the intersection lines of the respective blades being aligned with each other, the work-engaging surfaces of the respective blades lying in portions of a common plane, whereby the "tool may be drawn by said handle over a coated negative with the work-engaging surfaces engaging the face of the negative and the second surfaces of the respective blades being disposed in a plane substantially perpendicular to' the face of the negative.

'3. cutter for lining a photographic negative or the like, comprising an elongate handle, a holder at the end of the handle, a cutting tool removably mounted in said holder, said tool comprising a sheet metal blade having a substantially uniform thickness so that its opposite faces are parallel, the blade having an edge surface at its end which is remote from the handle which constitutes a work-engaging surface, the blade having a reentrant portion providing a second edge surface extending at an angle of the order of 90 to said work-engaging surface and meeting the same at an intersection line to afford a cutting edge, said line extending across substantially the entire width of the blade, said work-engaging surface extending at an angle of the order of 30 to the direction of extent of said handle, whereby the tool maybe drawn by said handle over a coated negative with the work-engaging surface engaging the face of the negative from which the coating has been removed and said second surface substantially perpendicular thereto.

GEORGE H. COLBURN. 

